Well bore enlarging tool



Aug- 15, 1939- J. J. SANTIAGO 2,169,502

WELL BORE ENLARGING TOOL Augl5, 1939. J. J. SANTIAGO 2,169,502

WELL BORE ENLARGING ,TOOL

Filed Feb. 28, 1958 2 Sheets-Sheet 2 f2' .5. H97 7 figa.

Invenfor.

Patented Aug. 15, 1939 UNITED STATES PATENT OFFICE WELL BORE ENLARGING TOOL Application February 28, 1938, Serial No. 193,056

2 Claims.

This invention relates generally to expansive Well bore enlarging tools, particularly of the type designed to cut or ream the well bore to a substantially larger diameter than the ordinary expansive tools used inv bore enlarging operations. In certain of its aspects the invention deals with improvements in swinging cutter reamers of the type described in U. S. Letters Patent No. 1,885,550, issued November 1, 1932, to me on Swinging cutter expanding reamer.

In this type of tool, the cutters are connected to the body by vertically swinging links which permit the cutters to have a comparatively large expansive range. One of my principal objects is to improve the cutter actuating means by providing within the body a single piston associated with the cutters so that the latter are expanded and contracted by the piston movement. The piston may be operated by spring or fluid pressure, or both. Preferably I utilize both spring and uid pressure to actuate the piston in its cutter expanding movement, and provide means whereby circulating fluid is conducted downwardly within the body to exert upwardly applied pressure against the piston. In View of other ifunctions performed by the circulating fluid pressure, I preferably conduct the iluid to the piston chamber through a tubular member carried by the piston, and through the piston itself.

Another feature of the invention is the provision of means whereby the expansible cutters of a reaming tool, and particularly of the present swinging cutter type, may be collapsed to- Ward or into the body by the circulating fluid pressure. For this purpose I may utilize a suitable object or go-devil that is dropped through the drill string to close or restrict the fluid passage through the cutter actuating parts, and thereby render such parts responsive to fluid pressure to collapse the cutters against an expanding force, such as that exerted by a spring. Specifically the go-devil acts to restrict the normally open passage through the piston carried tubular member referred to above, so that while normally the piston is'operable by fluid pressure to expand the cutters, when the go-devil is seated within the tool, the piston then becomes operable by the fluid pressure to` contract the cutters.

The invention also embodies an important fea- `ture applicable to the present tool, as Well as to other well tools having link connected parts, having for its object to prevent ldisconnection of the parts by the loss of pivot pins during operation. In accordance with the invention, the linksare vsectionallyformed and the pins are wholly contained within the links in a manner precluding the possibility of their removal from the joints.

The invention has a number of additional characteristics and objects, but all these, as well as the features mentioned above, will be understood to better advantage from the following detailed description of certain typical and illustrative forms of the invention. Throughout the description reference is had to the accompanying drawings, in which:

Fig. 1 is a longitudinal section showing one form of the invention with the cutters in collapsed positions;

Fig. 2 is a view similar toFig. 1 in which the cutter assemblies are shown in 'section and in expanded positions;

Figs. 3 and 4 are enlarged crossI sections on lines 3 3 and 4 4 of Fig. 2;

Fig.' 5 is a fragmentary enlarged section on line 5 5 of Fig. 2;

Figs. 6 and 7 are views similar to Figs. 1 and 2, showing a variational form of the invention;

Fig. 8 is an enlarged cross section on line 3 8 of Fig. 6;

Fig. 9 is a fragmentary longitudinal section on line 9 9 of Fig. l0, showing a further variational form of the invention comprisng a three cutter assembly with the cutters collapsed; and

Fig. 10 is an enlarged scale cross -section on line IIJ-I0 of Fig. 9, but showing the cutters in expanded position.

Referring first to Figs. 1 and 2, the tool comprises an elongated body I0 suitably attached to the drill pipe, as by threading the upper pin end II of the body into thelower end I2 of the drill pipe. The lower endof the body may be attached to a suitable tool, for example drill bit I3 having its upper pin end I4 threaded into the enlarged diameter body bore I5. The body is slotted or recessed to accommodate the cutter assemblies generally indicated at I6, any suitable number of ywhich may be provided, although I prefer to use a single pair of oppositely positioned cutters collapsible into a' centrally transverse and continuous body slot Il. Each of the cutter assemblies I6 comprises a rotating cutter I8 that may be of any suitable particular form and design, mounted on a pin I9 having at its upper end an integral enlargement and pivot lug 20a. The cutter assemblies are carried by upper and lower vertically swinging links 2I and 22, the lower links being shorter in length so that when expanded, the cutters assume the inclined position shown in Fig. 2. `A

As best illustrated in Fig. 3, each of the upper VWardly through the bore I5.

through slot I1 and between the pairs of links.

As best'illustrated in Fig. 2, the inner and bottom surfaces of links 2| are recessed at 28 to clear the rod 21 in both the expanded and coll lapsed positions of the links. The outer ends of the links are pivotally connected to the cutter pin lugs 23a by pins 29 which terminate within closed end bores 36 so that the pins are entirely contained within the links. This feature is of importance in that by no possibility canithe cutters become disconnected from the links by loss or dislocation of the pins 2S;

Nuts 32 carrying hinge lugs 33 are pivotally connected by links V22 with upwardly extending projections or fingers 34 on a cutter actuating piston 35 that operates in the lower body bore I5. As best illustrated in Fig. 5, the inner surfaces of the piston extensions 34 are recessed at 35 to accommodate rod 21, the latter being suitably attached to the piston, as Aby a welded joint at 38 (see Fig. 2) so that the rod travels vertically with the piston. Each of the link assemblies 22 comprises sections 22avand 22D having-bores 39 and 40 which receive pins 4I and 42 pivotally connecting the links to the pistonextensions 34 and lugs 33. Each link sections 22h is shaped or built'rup to provide cutting'edges k43, so that should the expanded cutters be lowered against a shoulder of smaller internal diameter than the effective cutting diameter of the lower ends of thev cutter I8, the outer ends of link sections 22h (the tool being rotated clockwise) will cut or ream away the shoulder ahead of the roller cutters. As in theY case of the pivotal connections of the links `with the upper ends of the cutter assemblies,

both sets of the lowerV link pivot pins :are Vconfined within the link sections, preventing their removal during Voperation of the tool.

In assembling the tool, and before bit I3 is attached, links 22 are connected to the piston extensions 34 and to lugs 33 before the piston 35 is inserted within'the body, and before the Ycutters I8 andA their pins I9 are attached to nuts 32. The piston 35, rod 21 and links 22 swung inwardlyabove the piston, are theny insertedupassemblies then are threaded into nuts 32, and nally the upper links 2| are assembled about a pins 29 and then vpivoted within the body slot operated, as by means of coil spring 5Ik seated Within bore 52 of 'the bit and bearing upwardly against the piston, o r by iluid pressure communi- 'cated-to bore I5, Yor by both spring action and fluid pressure.

for expanding the cutters, spring 5I constantly tending to raise the piston to cutter expanding position, and rod 2.1V serving to communicate fluid A The cutter and pinV Provisionpreferably is made for utilizing both spring pressure and fluid-pressure -walls of body slot I1.

through and beneath the piston to supplementV the spring pressure. The size (cross sectional area) of the bit fluid passage 50 is such that it restricts the circulating fluid ow to a greater degree than the maximum fluid restriction offered by the rod assembly 21, so that increased rate'of circulating fluid flow to the tool will result in increased fluid pressure within chamber I5 that is itself sufficient to actuate the cutters. As best illustrated in Fig-5, upward travel of the piston 35 is limited by engagement of inclined piston surfaces 35a between the extensions 34, with correspondingly inclined body shoulders 53. In the full expanded positions of the cutters, links 2| may be brought to engage the upper end 54 ofthe body slot so that during reaming operations, the links are supported' by the body against upward thrust communicated from the cutters.

In operation, the tool is inserted within the well casing, not shown, with the cutters confined Yagainst expansion under the influence of spring 5I,-by engagement with the casing wall. When lowered beyond the casing shoe, the cutters are released-for-expansion Vto `the degree permitted by the bore diameter below the casing. During reaming operations, andas previously mentioned, fluid-pressure'may be lcommunicated to thepiston chamber to increase theexpansive pressure on the piston, by increasing the rate` of fluid circulation to the tool. With the upper` and` lower ends of the cutter assemblies carried by the vertically swinging links as in the described j form `of the inventiomthe cutters are [not col-V lapsible by engagement of links 2| with the-casing shoe, and hence provision is required for collapsing the cutters independently of such engagement. In accordance with .the invention, piston 35V is movable downwardly to cutter collapsing position by fluid pressure communicated to the upper end of -rod 21. To collapse the cutters, a

- go-devil 56 is dropped through the drill pipe I2 into bore 46 to seat against'the upper end of the rod head 41. The go-devil 56 sufficiently restricts the uid passage-'above the rod that fluid pressure sirable that it be possible 'to maintain some fluid circulation past the go-devil, and Yfor this purpose the latter may be provided with a relatively restricted iluid course 51k of smaller cross sectional areaV than the smallest portion of the `iluid passage therebelow, i. e., the Abit passage'5Il. the point of` maximum pressure differential is at the go-devil, resulting in downward movement of the cutter actuating assembly and contraction of .the cutters.

In Figs. 6 to 8 I show a variational form of the invention generally similar to the first described form, but differing structurally-in that the lower lends of theV cutter assemblies, instead of being connected by links to the actuating'piston, are directly connected thereto.. Otherwise corresponding parts in the two forms are designated bythe same reference characters. Nuts 58 on the cutter pins are directly pivoted tothe piston bypins 60 passing Vthroughthe piston extensions 34 and terminating Within the spaced lugs 6I carried by the nuts. The' pins are confined against end `movement out ofY the VV`joints, by the As in the first described Thus form ofthe invention, the cutters are expansible -by thelaction of spring 5I,'and also by fluid presthrough the rod 2l. Here however the cutters may, if desired, be collapsed by engagement of links 2i with the casing shoe as the tool is being pulled up into the casing, the cutters thus being contractible by reason of the fact that the lower ends of the cutters are directly connected to the piston so that downward swinging movement of links 2i is transmitted through the cutters to depress the piston. While, as before, the cutters may be collapsed by fluid pressure through the use of the go-devil, ordinarily in the operation of this form of the invention, the cutters will be collapsed by engagement with the casing shoe.

Figs. 9 and 10 illustrate a further variational form of the invention whose construction and operation is similar in all respects to the preceding forms, except with respect to the cutter arrangement and the cutter receiving body slots. Here the tool has three cutter assemblies, generally indicated at 63, each comprising upper link assemblies 54 having inner reduced width portions Sa pivoted on pins S5 within intersecting body slots S5 of corresponding width. The inner ends of the link assemblies are recessed at 5l to clear the piston carried tubular rod 8. The outer ends of the links are pivoted at F59 to the cutter pins 1i), as before, and the lower ends of the cutter lpins may be connected to the upper end of the piston 'H either by links as in Figs. l and 2, or directly to the piston as I have illustrated at 'I2 in Fig. 9. The piston stop is formed by body shoulders 'i3 between upwardly projecting portions 'Ha of the piston arranged 120 apart in accordance with the cutter arrangement. In their contracted positions, see Fig. 9, the cutters are received within intersecting body slots 'lf3 of greater width, suiiicient to accommodate the cutters, than the link receiving slots 55. As will be understood, pivot pin l5 is suflciently oiset outwardly with relation to pins and l that vertical movement of the piston 'il will cause expansion and contraction of the cutters, all in the manner previously explained with reference to the rst described forms.

I claim:

1. A well reaming tool comprising an elongated body adapted to be attached to a drill stem, said body containing a transverse longitudinal slot, a pair of cutters radially contractible within said slot, a pair of cutter carrying arms pivotally connected to the upper ends of said cutters and mounted on` the body to swing vertically, a chamber and cutter operating piston within the body below said slot, a tube connected to piston and extending longitudinally through said slot into a body bore thereabove, said piston being movable upwardly by iiuid pressure communicated through said tube to said chamber, and means adapted to be dropped through the drill stem. into engagement with said tube whereby huid pressure applied to said means causes the tube and piston to move downwardly within the body, said means being apertured to pass fluid tube and restricting fluid iiow to a greater degree than the luid restriction offered by the tube bore.

2, A well roaming tool comprising an elongated body adaptedto be attached to a drill stem, a cutter expansively and contractively movable on said body, said body having a longitudinal cylinder bore in its lower portion and a longitudinal plunger borey in its upper portion, said plunger bore being substantially smaller than said piston bore, an apertured cutter operating piston in the cylinder bore, a longitudinal tube connected to the piston and extending upwardly therefrom into the plunger bore to pass iiuid pressure from the plunger bore to the. cylinder bore below the piston thereby to move the cutter operating piston upwardly to operate the cutter, said tube forming in` the plunger bore a relatively small tubular plunger, and means adapted to be applied to the upper end of said tubular plunger to restrict its tubular passage whereby fluid pressure applied to said means causes the tube and piston to move downwardly within the body, said f means being apertured to pass uid into said tube and. restricting fluid ilow to a greater degree than the fluid restriction offered by the tube bore.

' JAMES J. SANTIAGO. 

